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Comments 1 to 50 out of 61:

1. Leland Palmer at 08:36 AM on 18 August, 2014

   Regarding the changes in the Arctic, those Siberian Yamal Peninsula craters and the other Arctic methane stories are seriously scaring me. Not only are the stories about large methane emissions from the ESAS recorded by the oceanic expeditions scary, but so are the news stories above and the implications of the new explosive mechanism for releasing methane by methane eruption events. 

   Looking at Siberia with Google Earth, large areas are covered with tens of thousands of circular lakes and circular landscape features, and some of them are ten miles or so across. It seems possible that those tens of thousands of circular depressions were generated by similar methane gas eruptions, followed by melting of ice and methane hydrate and subsidence to enlarge the initial gas eruption craters.

   Andrey Plekhanov, Senior Researcher at the State Scientific Centre of Arctic Research, thinks this might be the case:

   

   http://siberiantimes.com/science/casestudy/news/first-pictures-from-inside-the-crater-at-the-end-of-the-world/

   Quoting Plekanhov- “‘I also want to recall a theory that our scientists worked on in the 1980s – it has been left and then forgotten for a number of years.

   ‘The theory was that the number of Yamal lakes formed because of exactly such natural process happening in the permafrost.
   ‘Such kind of processes were taking place about 8,000 years ago. Perhaps they are repeating nowadays. If this theory is confirmed, we can say that we have witnessed a unique natural process that formed the unusual landscape of Yamal peninsula.”

   The Yamal area gas fields, by the way, have been supplying large quantities of natural gas to Russia and Europe for decades, so there is a lot of methane in the area. Looking on Google Earth at the areas of Siberia that contain those giant methane gas fields, they seem pockmarked by thousands of circular lakes and other landscape features. There seems to be a visual correspondence between gas fields and the thousands of possible past methane eruption/subsidence craters.

   We need to do a realistic calculation to of the methane generated by the hundreds of thousands of square kilometers of circular Siberian landscape features which could plausibly have been generated by this process.

   Since erosion might soon erase such landscape features, it seems possible that most of the circular features visible using Google Earth were generated in a burst of methane gas eruption activity a few thousand years ago, perhaps in the early Holocene, as Plekhanov suggests.

   Perhaps, no realistic scenario exists that would release sufficient methane rapidly enough to make a big difference. But, our rate of change of temperatures in the Arctic is very, very rapid, and a similar burst of methane eruptions might occur more rapidly now than in the early Holocene.

   And, of course, these possible widespread methane gas eruptions are not the only change occurring in the Arctic, as permafrost melts and decomposes.

   What are the possibilities of similar eruptions occurring in the shallow waters of the the East Siberian Arctic Shelf, as the shallow underwater permafrost there melts and potentially uncaps more reservoirs of methane?

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2. Leland Palmer at 09:05 AM on 18 August, 2014

   Seriously, I invite other readers to look at the areas on this natural gas field map of Siberia in Google Earth, and see if they see the same correspondence between gas fields in the present and possible erruption craters in the past as I do:

   

   The Yamal Peninsula is in the upper part of the image, in the left center. But most or all of the major gas fields marked on the map seem to be seriously pockmarked with thousands of possible methane eruption/subsidence craters, when you go to the corresponding areas in Google Earth and look for them. 

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3. Tom Curtis at 09:40 AM on 18 August, 2014

   Leland Palmer @1&2, Real Climate had a recent article on the release of methane by eruption craters:

   "If the bubble was pure methane, it would have contained about … wait for it … 0.000003 Gtons of methane. In other words, building a Shakhova event from these explosions would take approximately 20,000,000 explosions, all within a few years, or else the climate impact of the methane would be muted by the lifetime effect."

   As a further sanity check, those thousands of lakes probably formed during the transition from the last glacial to the current interglacial.  That transition did not trigger a massive methane driven global warming event.  Therefore they are not evidence that the current warming will do the what did not occur when they were formed.

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4. jenna at 10:05 AM on 18 August, 2014

   Thanks to Tom @3 for posting the link to the Real Climate article. I knew I had read that "sanity check" about methane releases somewhere but couldn't find it. Let's all breahte a sigh of release on that one!

   Jen

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5. Tom Curtis at 10:21 AM on 18 August, 2014

   jenna, I'm not sure "breathing a sigh of releif" is the appropriate reaction in that we have got genuine problems enough from global warming.  Perhaps, let's just not buy trouble when we are in over our ears already.

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6. Leland Palmer at 10:56 AM on 18 August, 2014

   Hi Tom Curtis-

   David Archer of Real Climate essentially calculated how much methane it would take to fill a hole the size of the current crater in Yamal, under a certain amount of pressure. It's not really a very big crater, and is less than 100,000 times the area of some of the large circular lakes on Yamal.

   I would like to know how much methane would be released if Plekhanov's mechanism for forming the tens of thousands of circular lakes in the area is correct. It's not at all the same calculation, and the results could easily be different by millions of times.

   It seems strange that there would be two geological processes for forming circular holes in the same area. This seems to violate Occam's Razor.

   It seems strange that the circular lakes seem to concentrate in the same vicinity as current huge gas fields supplying a substantial portion of Europe's natural gas.

   I don't want to borrow trouble, but I don't want to hide from it, either.

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7. Tom Curtis at 12:18 PM on 18 August, 2014

   Leland Palmer @6:

   1)  The current crater is of the same size as the "thousands" of little lakes on the Yamal peninsular, as can be seen by the video on the article to which you link, and which speckle the photo you showed.  This is particularly the case as erosion will fill the great depth of the creater by broadening the surface diameter.  It is not the same diameter as the large lakes that dominate that picture, but there are not thousands of such lakes.  Rather, there are about 34 of them, with the cluster of lakes in the picture being both the largest such cluster, and containing the three largest lakes on the peninsular.  You can do your maths on the thousands, or on the thirty four.  What you cannot legitimately do is do the maths on the three largest out of the 34 lakes, and multiply that out by the "tens of thousands".

   2)  The lake with the largest diameter, and the most circular of the three large lakes in the cluster has a diameter (generously) of 16 km, giving it at most an area 40,000 times that of the crater analysed by Real Climate.  Based on that, the formation of the entire lake cluster would have released approximately 3 x 40,000 x 0.000003 (= 0.36 Gtonnes of methane) or 0.72 ppmv of methane.  That is a 40% increase on the current concentration, but only 0.7% of a Sarkhova event.

   You can argue details of that calculation.  I would argue it is a probable overestimate in that the lakes were likely formed by the formation of a number of smaller crates which were then joined by erosion.  To that point I note that they are not circular, and most of the large lakes are not even close to circular.  Against that you might argue that a crater formed with a larger diameter would also have a greater depth of the methane chamber exposed, and hence more methane overall.  While possible (indeed, probable for the intermediate and actually circular lakes of which there are many), it is invokeing a greater complexity in the phenomenon, and hence runs up against ockham's razor itself.

   3)  Regardless of how we do the maths on the lake complexes, for them to even contribute a 10% Sarkhova event, all the lakes and small craters must have formed more or less simultaneously.  Even spaced out over a few centuries the rapid conversion of methane to CO2 in the atmosphere would mean the forcing would be best modified by a 1 or 2 ppmv increase in atmospheric CO2, which is inconsequential. 

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8. Leland Palmer at 12:22 PM on 18 August, 2014

   I don't think that Plekhanov and his collaborators are proposing that the large circular lakes on the Yamal Peninsula were formed exclusively by an explosive process.

   What he is saying, I think, is that an explosive eruption creates the first deep crater. That crater has a lake in the bottom of it. The lake undercuts or weakens the edges of the crater, and the edges keep falling into the deep crater. So, the craters enlarge in diameter but get much shallower as this process continues for decades or centuries. 

   But, during the enlargement process, I'm afraid that much more methane will likely be released than was released during the initial gas eruption.

   Without the evidence of the crater itself, this whole process seems unlikely, which may be why the original hypothesis died in the 1980's- for lack of evidence. 

   Suddenly, though, with the generation of these 3 craters, the logic changes. Project the processes we see at work on this crater into the future, and what we get is a circular lake, just like the tens or hundreds of thousands of other circular lakes in this area of Siberia.

   Saying that there is another explanation for these circular lakes suddenly seems to violate Occam's Razor. We would be postulating an unknown process to explain them, when we already know one process that could produce them - the eruption plus progressive enlargement process.

    

   Except, the other lakes in the area are much, much bigger. One of the lakes near the Yamal crater is about 10 miles in diameter - at least 100,000 times the area of the current Yamal crater. So the inital eruption that may have produced this lake would have had to be much, much larger than the current Yamal eruption.

   Can we safely ignore this chain of logic, and hope that there really are two unusual processes producing circular holes in these same geological areas, which just happen to sit above giant natural gas fields?

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9. scaddenp at 12:24 PM on 18 August, 2014

   Even if all the "lakes" are methane craters, it is still not an issue if they formed over the whole of the holocene. Archer is asking how many craters do you need a relatively short period before there is problem. The methane in atmosphere from past outgassing of hydrates is clearly not an issue so you can only have a problem if there is a huge increase in rate. Without some detail on geology and detailed morphology of lakes, it's a bit premature to conclude that they are methane eruptions. Simple thermokarst lakes seems at least as likely.

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10. Leland Palmer at 12:50 PM on 18 August, 2014

    Hi Tom Curtis-

    Yes, we can argue the math. But we do have a process going on - abrupt global warming in the Arctic - which could produce very large numbers of simultaneous eruptions- and we don't know that they come in only one size. This mecanism could produce enough eruptions, of various sizes, perhaps, to fit Archer's reqirements for concern.

    Global warming can also simultaneously produce other, perhaps larger, emissions of methane.

    Or, this new explosive release plus slow subsidence mechanism could be the answer to the riddle of past methane catastrophes. This mechanism could form a bridge from a triggering mechanism like orbital forcing or a flood basalt eruption to a general release of methane from the oceanic methane hydrates.

    Why draw a distinction between the large Yamal lakes and the smaller ones? Looking at the topography, which I urge you to do, these circular lakes come in all sizes. Perhaps the large ones are the result of the fusion of multiple eruption craters, but what we are concerned about the most is the total amount of methane released.

    Do you believe that there is a bimodal size distribution? If so, that's interesting, and could be a clue to the nature of the process.

    We're concerned about the total amount of methane released, not the amount released from any single event- or even the amout release by any single mechanism.

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11. Leland Palmer at 13:15 PM on 18 August, 2014

    Hi scaddenp-

    I hope you are right, about the thermokarst. Phekhanov and his collaborators seem to take the eruption hypothesis seriously, though, and surely if anyone would know about thermokarst, these Russian scientists would.

    Our modern rate of waming is much faster than past events, and is certainly much more systematic. Past events have not had the terrible consistency of human fossil fuel based climate forcing. So, things that took a couple of thousand years in the early Holocene could easily take only a hundred years now. 

    I'd like to see a serious calculation done, one that looks seriously at how much methane could be released by a realistic distribution and number of eruption events and a realistic duration of subsequent slow subsidence events. Nobody has done that, yet, that I know of, and I look forward to seeing the results.

    I'm not convinced by Archer's calculation - it could easily be off by a factor of 10 or even 100, if methane continues to flow into the crater over decades or centuries.

    And this first eruption event could be a tiny one, compared to the ones that may come.

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12. Leland Palmer at 14:11 PM on 18 August, 2014

    Hi Tom Curtis-

    "The current crater is of the same size as the "thousands" of little lakes on the Yamal peninsular, as can be seen by the video on the article to which you link, and which speckle the photo you showed."

    Oh, I wasn't just talking about that one area of the Yamal Peninsula, Tom.

    I was talking about the probably hundreds of thousands of generally circular lakes, of all sizes, that cover maybe 5 percent or so of the 13 million square kilometers of Siberia, and even a couple of small areas of the Canadian Archipelago. I urge you to fly around a little using Google Earth, and tell me what you see.

    I really, really hope that they are due to thermokarst processes. I hope that there is another explanation for the apparent association of these lakes with the huge methane gas fields in the area. Occam's Razor works better with simpler systems than the whole planet, and two processes producing similar looking holes operating in the same area is not impossible - it just seems unlikely to me.

    I really hope we will not see an accelerating series of methane eruption events- of all sizes- as the permafrost thaws, and subsequent slow releases of methane from enlarging craters. So far, we've apparently seen 3 such events - and it only takes two events to make a pattern.

    But, thawed permafrost is weaker than frozen, and heated gas expands, and we are heating millions of square kilometers of permafrost with our human caused global warming. 

    And, the laws of physics and chemistry will not change just because we want them to. Ice still melts and gas still expands, and we really should not be surprised if the unexpected happens when we experiment on an entire planet.

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13. chriskoz at 14:25 PM on 18 August, 2014

    Leland Palmer,

    You seem to be missing the final point of David Archer's RC article:

    In conclusion, despite recent explosions suggesting the contrary, I still feel that the future of Earth’s climate in this century and beyond will be determined mostly by the fossil fuel industry, and not by Arctic methane. We should keep our eyes on the ball.

    Maybe because David did not clearly compare his GHG numbers coming from this "hole from the end of the world" with the FF emission numbers.

    So let's try to hypothesize and assume the worst, that this hole is heralding a new PETM-like event. What type of CH4 emissions and what magnitude of GHG forcings can we expect as the result of such bold assumption? There is extensive literature on that subject. Let's take for example Schmidt & Shindell 2003, their Table 2 on p4 lists the possible PETM scenarios. The scenario David is talking about is the release of couple Gt/y on a short timescale. That corresponds roughly to this row in said table:

    Experiment: 0.3 Gt/yr (5 kyr)

    Atmospheric Concentration Increase (ppmv)

    CO2 : 100

    CH4 : 1.8

     

    H2Ostr: 0.6

    Forcing (W/m2)

    CO2: 1.9

    CO2+CH4: 2.6

     

    Note the CO2 increase of just 100 (compared to antropo 120 already and rising). Also note the forcing in bold: it is about the same level of forcing antropo emissions have already achieved and rising. That should be really scary to you, not your tale from "the end of the world".

    So, according to your own ockham's razor principle, you should be looking at the hints of what's already happening, rather than  at the unsubstantiated speculations. To give you the examples of latest developments that should look "scary" to you, read those economic/political events/comments that incidentally could have been the topics of this Roundup. The news are from my part of the world. I don't know what part you live in, perhaps closeby as you're posting at the same time herein.

    Claims of Australia's biggest oil discovery in 30 years

    The dicovery is not that surprising to me. But the fact that:

    Shares in Australian company Carnarvon Petroleum, a junior partner in the venture, instantly more than doubled on the news

    look scary to me. Another scary news is the comment by this guy (the current OZ PM business advisor):

    Climate change measures like 'primitive civilisations offering up sacrifices to appease the gods', says Maurice Newman

    which means the politicians are complete nutters and ignorants when it comes to the AWG problems.

    That's the ball David warns that you should keep your eye on. The methane tale should not obstruct that view.

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14. scaddenp at 14:37 PM on 18 August, 2014

    But I would also note you have such lakes and landscapes without any gas fields. Leakage of methane from thermogenic reservoirs can definitely create methane hydrates but they have a different chemical and isotopic signature to biogenic hydrates that are normal for permafrost. I didnt find data for Yamal though in a quick look. Do you know of any? Examples of analyses from elsewhere in Siberian permafrost can be found here. Occam's razor only applies when you have hypotheses that can equally explain the data. I am not sure the data shows that.

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15. Leland Palmer at 14:57 PM on 18 August, 2014

    Hi chriskoz-

    To make it short and sweet, methane is scarier than CO2 because of the carbon isotope excursions associated with past mass extinction events like the End Permian, plausibly due to the release of trillions of tons of methane from the oceanic methane hydrates. The End Permian killed upwards of 90 percent of all species- surely more than 99% of all individual organisms. And the sun is hotter now than it was then, by a couple of percent- an effect Hansen says is equivalent by itself to 1000 ppm of CO2.

    Two major greenhouse gases is much scarier than one, mainly because infrared absorption bands get saturated, and because of the ability of methane extend to extend its own lifetime through degradation of the hydroxyl radical degradation mechanism. And three major greenhouse gases is worse than two, if you figure that water vapor will increase about 7% per degree of warming, whether that warming is due to CO2 or methane.

    Then there are the atmospheric chemistry effects of methane, and the oceanic chemistry effects of methane. 

    Strong atmospheric chemistry feedback to climate warming from Arctic methane emissions

    "The indirect contribution to RF of additional methane emission is particularly important. It is shown that if global methane emissions
    were to increase by factors of 2.5 and 5.2 above current emissions, the indirect contributions to RF would be about 250% and 400%, respectively, of the RF that can be attributed to directly emitted methane alone. " (RF is an abbreviation for Radiative Forcing)

    For the oceanic chemistry effects of methane, read Peter Ward's book "Under a Green Sky".

    No, methane is definitely scarier than CO2. The runaway feedback effects of methane are far, far scarier. 

    Methane is why we need to ban fossil fuels, not just decrease their use.

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16. Leland Palmer at 15:14 PM on 18 August, 2014

    Hi scaddenp-

    "But I would also note you have such lakes and landscapes without any gas fields." Maybe. Some areas could be depleted enough by the eruption scenario of 8000 years ago that they fall below the threshold for commercial desirability. Or maybe there are such lakes and landscapes, currently free of methane. Or, maybe nobody has happened to drill in those areas. It's too soon to know, the hypothesis is still too new. 

    "Leakage of methane from thermogenic reservoirs can definitely create methane hydrates but they have a different chemical and isotopic signature to biogenic hydrates that are normal for permafrost. "

    Huh? Who said anything about thermogenic methane? Most of it is of bacterial origin, and certainly isotope ratios can be used to investigate the origin of the methane, but so far as I know, we are talking about normal C13 depleted C12 enriched bacterially generated methane in the eruption scenario, with a bit of random thermogenic thrown in. 

    Having said that, it looks like an interesting link, and I'll read it. I'm not sure that how that applies to this eruption scenario, though. 

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17. scaddenp at 15:17 PM on 18 August, 2014

    The natural gas fields that you are associating with the methane hydrate are deep thermogenic gas.

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18. scaddenp at 15:23 PM on 18 August, 2014

    I wouldn't get too carried away with PT extinction. Hydate release is but one hypothesis and like the others has it's strengths and weaknesses. Hydrate release could have been a contributing side-effect with others being the cause. The globe was a very different place in PT, including have much larger areas of shallower seas (and thus hydrates). It is an interesting problem but not one that you can use to draw too many conclusions about what might happen in the modern world.

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19. Leland Palmer at 16:05 PM on 18 August, 2014

    Hi scaddenp-

    "The natural gas fields that you are associating with the methane hydrate are deep thermogenic gas."

    I don't recall saying that these gas eruptions are associated with methane hyrates -just that they could be. I don't know that there are hydrates in the eruption craters, I just said that assuming only gaseous methane under pressure makes the calculated release smaller, I think. Maybe there are hydrates associated with these eruption events, maybe not. Maybe the methane is biogenic, maybe it's thermogenic. Permafrost can contain hydrates, but we don't know yet that these eruption events are associated with hydrate.

    About the PT extinction, if I don't get carried away about that one, there are a series of carbon isotope excursions associated with extinction events that I can get carried away about instead. The largest calculated methane release I am aware of in a peer reviewed paper is one that claims a total release of about 12 trillion tons of carbon (16 trillion tons of methane) during the End Triassic. 

    There are hundreds of peer reviewed scientific papers that agree with the methane release explanation for the carbon isotope ratio excursions associated with a variety of mass extinction events. So, what would you be willing to bet that they are wrong? Would you bet the planet on it, for example?

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20. chriskoz at 23:30 PM on 18 August, 2014

    Leland@15,

    The study you cite explicitly says:

    Although the high‐CH4 scenarios applied in this study are unlikely, they demonstrate the strong CH4 feedbacks in the climate system, with large amplification of atmospheric composition changes and RF compared to the direct RF of CH4 emissions.

    I would use even strongeer language: "very unlikely". 2.5 times the rate of current CH4 emissions is where they start their experiments. Note, the current emissions (500Mt/y of which about third can be antropo emissions from FF leakage) already have been shown to be the central estimate of PETM rates (if sustained over several ky). This is the real problem. And the CO2 rate is much larger: 10GtC/y and growing. The potential addition to that rate from thawing permafrost has been shown to be miniscule by comparison.

    Expert like David Archer repeat that permafrost feedback is very slow. When talking about deep geological past in search for examples that unleashed said feedback, we need to be aware of the necessarily very long timescale of such events. I speculate (i'm not expert not even familiar with the processes triggering them) they can be even slower than for example orbital forcings. If it wasn't so, then we would have observed such feedback more frequently in the past (say every few orbital cycles of 100ky, rather than only couple in the entire 65My history of Cenozoic).

    So, it is unlikely that 2.5 the rate of CH4 feedback will kick in next couple hundred y. The problem of FF emissions is occuring at least 100times faster, therefore its effects may come and go (assuming people grow up to the task of successful mitigation and end up with zero emissions soon), before permafrosts starts thawing. That's IMO the most likely scenario, based on our best knowledge, without scaremongering.

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21. Leland Palmer at 00:22 AM on 19 August, 2014

    Hi chriskoz-

    Archer thinks he can predict what will happen.

    I don't think so. 

    We've now seen three cold gas eruption events. Does anyone doubt that there will be more?

    This new explosive release plus slow subsidence mechanism needs to be factored into all future scenarios. We need to find out- urgently- how much methane this mechanism will release, and how much it has released in the past.

    Beyond that, we need to just stop experimenting on our planet, and introducing factors that no one is competent to predict. Isaksen wrote his paper before he knew about this new explosive release mechanism. I wonder what he would say, now.

    The laws of physics will not be denied. Permafrost melts and gas expands when heated. Heat millions of square kilometers of permafrost, and we run the risk of setting off side effects that no one is competent to predict.

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    Moderator Response:

    [JH] You are now skating on the thin ice of excessive repetition which is prohibited by the SkS Comments Policy. 

22. scaddenp at 07:17 AM on 19 August, 2014

    The mechanism proposed so far by Phekhanov and others is for pressure release of hydrates as the tundra has warmed. This is plausible. I dont see a plausible mechanism for the crater from release of deep thermogenic gas, and if one was shown to exist, it certainly wouldnt be related to global warming. The other events you mention are still associated with a continental configuration including large shallow seas and thus potentially lots of hydrate. Got a paper that claims the excursions are from a spontaneous release of hydrates? I am familiar with PT and PETM literature but I admit to know little about a Triassic event.

    What Archer and others are pointing out, is that is very difficult to find a credible mechanism for producing dangerous amounts of CH4 in the modern world, which makes such claims unduly alarmist. Far from being out by 10 or 100, I think you should note that Archer used an impossible upper end for methane content.  We have quite enough problems with CO2 emissions. Truly alarmist claims simply result in lost crediability and distract from the real problems.

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23. Leland Palmer at 15:53 PM on 19 August, 2014

    Hi scaddenp-

    OK, one more (new - Moderator please note) point and then I'll shut up, at least for a while.

    I think Archer may have missed the point, by considering only the initial release of methane. The crucial question might be - how much methane (which is lighter than air and so is bouyant) would have to be released at a constant rate to maintain an equilibrium concentration of 9% in the bottom of such a crater for a long period of time? The measured concentration at the bottom of the crater a couple of weeks ago was 9%.

    From Wikipedia:

    "Dry air has a density of about 1.29 g/L at standard conditions for temperature and pressure (STP). Methane (density 0.716 g/L at STP, average molecular mass 16.04 g/mol) is the chief component of natural gas and is sometimes used as a lift gas when hydrogen and helium are not available."

    To maintain a constant concentration of a bouyant gas must require a constant flow of methane into the crater.

    My spreadsheet calculation says that about 82 kg per second of methane would be released to maintain that 9% concentration, as a very rough approximation using Newton's laws of motion and making conservative assumptions.  That's assuming a 25 meter square column of gas that is 9% methane and 100 meters high is providing the bouyant force. I get an acceleration of about 0.04 meters per second squared, and a final velocity of about 2 meters per second for the entire column of 9% methane.

    So, over 100 years, that's about 0.3 gigatons of methane - roughly 100,000 times Archer's number.

    That seems high, no doubt that flow would decline over time. At least, I hope it would. As the flow declines, the bouyant force would also decline. Still, it looks like Archer was asking the wrong question, by limiting himself to a calculation of the initial methane release, and was likely low by a factor of at least 1000.

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24. Leland Palmer at 16:02 PM on 19 August, 2014

    Woops, that's in billions of kilograms, not in billions of metric tons. So, make that 0.0003 gtons- still a factor of 1000 greater than Archer's calculation.

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25. scaddenp at 19:18 PM on 19 August, 2014

    Um, are you not implying because methane is lighter than air, it must all go up? In what way is that different from the idiots that claim that CO2 must stay close to ground because it is heavier than air? The change in gas concentration in the crater must be governed instead by gas diffusion laws.

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26. michael sweet at 19:53 PM on 19 August, 2014

    Scaddenp,

    I think in this case it is possible for the methane to rise because it is not well mixed.  If the gas in the hole has a higher concentration of methane than the surrounding air it will be less dense and move as a bulk.  Once out of the hole, wind will mix the bulk around and distribute the methane.  Once it is well mixed it no longer rises.  I do not know how to do the calculations,  but it has to be considered.

    Carbon dioxide can be held in a covered container because it is heavier than air.  If the cover is removed the CO2 will stay in the container for a long time until air currents slowly mix it with the surrounding air.  Hydrogen can be contained in a container with an open botton.

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27. chriskoz at 21:20 PM on 19 August, 2014

    Leland@23-24,

    While your idea of calculating the hole's emission rate from the measured equilibrium concentration at the bottom is interesting, your results are simply laughably exaggerated, even after the correction by a factor of E3 @24.

    82kg/s, that's about 120m³ of pure methane per second! Do you see sizeable vents in the walls of the crater that would possibly provide such big flow? No way. Therefore your methane delivery would have to happen from the water at the bottom. Do you imagine the size of bubbles? This water would not look like a quiet puddle on the movie they've shown but rather like a boiling cauldron from hell. No one would be able to even approach the crater and abseiling along the wall as they've done to film the puddle would endup in suffocation.

    I don't bother following your calculatrion/verifying your numbers. But I feel like your statement:

    [my rate is] a factor of 1000 greater than Archer's calculation

    actually favours Archer, because your rate seems like 1000times greater than the reality (which is a quiet puddle, not a roaring cauldron). I would not be surprised if the expert's calculation estimated hole's emission at ~80g/s exactly 1000times less than yours, in par with Archer's calculation. Said emission, coming from cracks in the bottom and tiny bubbles in water mixes with the air volume at the bottom 1m of the crater and results in 9% concentrate as measured by some hand-held spectrometer. The spectrometer gives the highest readings of 9% in the pockets close to the vents at the bottom. By the time that methane reaches the lip, it's already dilluted close to the background levels. Proof: the abseiler who filmed it did not hesitate to go and apparently survived. 

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28. Leland Palmer at 00:27 AM on 20 August, 2014

    Hi chriskoz-

    Well, the total area of the walls of the crater is about 71,000 square meters, assuming a 15 meter radius and a depth of 100 meters. So, that's about 1.6 liters of methane per second per square meter of crater wall. 

    Is that excessive?

    I wonder how much methane is coming out of this crater in Turkey? It's been burning for 40 years, I guess.

    

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29. scaddenp at 06:30 AM on 20 August, 2014

    Michael, I dont follow. I cant see how methane can diffuse out of the hole faster than the mixing rate on the interface. Yes, CH4 will be faster than CO2 because diffusion rate is dependent on inverse square of molecular mass, but surely Graham's law more or less applies. I dont see the setup being any different to high school diffusion rate experiments really.

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30. scaddenp at 07:50 AM on 20 August, 2014

    1.6l/m2 for be a very respectable flow rate for a deep natural gas reservoir with its enormous pressure. That kind of permeability in tundra? with almost no pressure?

    Your crater photo is methane coming up from a deep thermogenic gas reservoir under enormous pressure. Gas seeps are common (I have a database of around 600 of them from around NZ) and their flow rates have little influence on atmosphere. Its revelance to methane from tundra/hydrates would be nil. Now it is possible the methane in the Yamal crater is from deep thermogenic gas field but then it would have no relevance to climate change at all.

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31. scaddenp at 09:10 AM on 20 August, 2014

    I should say though that a long time scales, (100kya),  thermogenic gas could be a significant feedback. This paper by two of my colleagues show what happens from a very cursory look and with just commercial modelling software. We havent been able to pursue the matter sadly. The paper also shows that on human time scales, thermogenic gas isnt much of an issue for climate.

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32. Tom Curtis at 11:13 AM on 20 August, 2014

    Leland Palmer @12 and @23 switches the basis of the discussion from single one time releases for the event, to estimated ongoing releases.  In doing so, he estimates an ongoing flux which releases an equivalent amount of methane in 10 hours to the amount estimated to have been released in the explosive release by Archer.  I am not alone in finding that implausible.  

    What ever factors currently contribute to release of methane from the crater must have previously contributed to release of methane into the chamber.  As the amount of methane was presumably stable, with the explosive release of the methane due to weakening of the chambers roof by warming (either the ongoing global warming and/or the recent locally hot summers in the region), that means the less than 10 atmospheres pressure in the chamber was enough to prevent the current release rates.  That in turn suggests current release rates are likely to diminish rapidly as methane becomes depleted from the crater walls.  Therefore, any such calculation as made by Leland should wait until gas concentrations at the bottom of the crater stabilize (even assuming he uses the correct method).

    More importantly,  the contribution of long term slow releases of methane cannot be reasonably estimated without taking the oxidation rate of methane into account, which is sufficient to halve methane content in the atmosphere every seven years.  (That means to maintain the current 1.85 ppmv of methane in the atmosphere the equivalent of half of that must be emitted from all sources every seven years, and in fact slightly more than that as concentrations are growing.)  It is because of this oxidation that Archer is not overly concerned about high arctic methane emission, and why methane catastrophes such as proposed by Shakhova assume emissions of 50 gigatons 1-5 years.  (Even such a Shakhova event, which temporarilly increases atmospheric methane by as much as 1100% would only increase atmospheric temperatures by a further 1.3 C at the end  of the century.) 

    Leland's estimate of ongoing emissions from the crater represents just 0.00003% of a Shakhova event.  Even the erruption of 50,000 such craters over the next 5 years would represent just 1.5% of a Shakhova event.  At the moment there is no data that suggests such a rapid erruption rates is likely, and hence no data suggesting this erruption pressages an imminent Shakhova event.

    As a footnote, @28, Leland shows a picture of the "Door to Hell" in Turkmenistan (not Turkey).  Although it has been burning for 43 years, the methane in question is thermogenic, and part of a major oil and gas field.  The duration of the burn is in no way an indicator of the likely sustainable flows of the biogenic methane that is likely being released from permafrost in Yamal.

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33. michael sweet at 11:30 AM on 20 August, 2014

     

    Scaddenp,

    If a tank of methane failed the gas would rise in the atmosphere as a body, since it is less dense than air.   This is the same as hot air rising over a fire.  Eventually it would mix with the surrounding air.  Once the gas is well mixed it would no longer rise.  CO2 is always described as well mixed when the properties of the gas in the atmosphere are discussed, mixtures enhanced in CO2 or methane would behave differently.

    At the volcanic lakes in Africa the CO2 flows over the ground after sudden release from the lakes, suffocating nearby villagers.  After the gas mixes with the air it no longer hugs the ground.

    I do a demonstration where I pour a cup of CO2 over a candle. link  The CO2 sinks through the air and the candle goes out.  It is possible (looks much cooler) to pour the gas from one beaker to another and than over the candle.  Methane will rise when it is in high enough concentration.  For this reason propane is dangerous in boats.  The propane can sink into the bilge and accumulate.  Occasionally you see reports of boats exploding from propane leaks.  The propane does not leak out since air currents in a sealed boat are small.  Methane floats out and does not usually accumulate in boats (or houses).

    In this hole it seems to me that enhanced methane containing air could rise out of the hole at a much faster rate than it would diffuse out.  Air would siphon in the other side.  Once out of the hole, wind would rapidly mix it and it would stop rising. 

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34. scaddenp at 12:36 PM on 20 August, 2014

    Okay Michael, I get it (and hurriedly consulted textbooks). However, we could reasonably assume that by the time they measured it, you had well-mixed gases in the hole (only 9% was methane) and so any new ingress into the hole would only be only leaving at something like diffusion rate assuming no wind.

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35. Leland Palmer at 16:17 PM on 20 August, 2014

    scaddenp-

    " Now it is possible the methane in the Yamal crater is from deep thermogenic gas field but then it would have no relevance to climate change at all."

    This simply does not compute, sorry to say. The origin of methane has absolutely noting to do with it's relevance to climate change. Thermogenic methane has somewhat different C12 to C13 ratios than biogenic methane, is all. It all has the same greenhouse effect, no matter what the source.

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36. Leland Palmer at 16:41 PM on 20 August, 2014

    Hi michael sweet-

    Yes, of course a bouyant gas will rise, until it becomes well mixed with the atmosphere. 

    Inside the Yamal crater, I suspect that what is going on would be a bouyant plume of methane that would rise, until it clears the rim of the crater, and it would then be mixed with the rest of the atmosphere. I suspect that the bouyant plume would be concentrated toward the center of the crater. I suspect that air would flow down the sides of the crater, to fill the space left by the exit of the bouyant plume. I suspect that the air flowing down the sides of the crater would help melt the walls of the crater, and increase the erosion rate- part of the natural process of evolution of the crater, leading ultimately to a circular lake.

    It may be that my calculation was too high - I was assumng that most of the volume of the crater was 9% methane. If that 9% figure was only around some vents at the bottom of the crater, then the bouyancy driven circulation would be less. By the way, my calculation results in gas flows of 4 miles per hour, or so - walking speed.

    I suspect that methane concentration measurements around the rim of the crater would be low- likely this is in the influx stream of air leading down into the crater. What I would be interested to know is the concentration of methane in the bouyant plume toward the center of the crater, and the rate of flow in a cross section across the top of the crater.

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37. michael sweet at 20:10 PM on 20 August, 2014

    Leland,

    I doubt that an estimate of the gas flow into the crater can be made from the very limited data that has been released.  Presumably the scientists who made the measurements will release their estimates when they finish their calculations.  It will be interesting to see what they find.

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38. scaddenp at 20:23 PM on 20 August, 2014

    "This simply does not compute, sorry to say".

    The speculation is that crater is result of shallow methane hydrate melting due to global warming and releasing methane. The pressure of methane builds up till it blows out the cap rock. There are no vents involved and the origin of the methane is in immediate sediment around the hole. If this is correct, then the crater is related to global warming since it depends on warming of the sediments to release the methane. I would note that there is no mention of any vents in descriptions of the craters so far.

    If the methane is thermogenic, then it is finding its way to the surface via fractures from a reservoir, probably at around 50Mpa, 2km below the surface. This is the origin of the "Door to Hell" seep. I struggle to see how global warming can have any impact on this process. Furthermore, I would expect a gas seep at the bottom of the crater linked to a fracture system. Gas from such a system would continue to leak as it does in numerous other places at rates entirely unaffected by climate, at least on human scales.

    For my money, I would back the shallow methane hydrates as source, caused by warming of the tundra, that the sources are local and temporary. (after the pressure release surrounding sediment would quickly give up biogenic and hydrate methane but the sediment permeability would be unlikely to allow a large area to drain).

    I looked more carefully at Archer's calculation. He not using the 9% measurement. He is assuming bubble is the same volume of the hole and that it is 100% methane at pressure of 10 atmospheres. That is surely an upper bound.

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39. Leland Palmer at 00:34 AM on 21 August, 2014

    scaddenp-

    I get what you are saying, now. But I think climate change is still relevant to the release of methane, whatever the source. 

    It's the melting of the permafrost cap that allows the eruption event, the hypothesis goes. Frozen permafrost is strong and able to resist pressure from below, melted permafrost is weak and susceptible to eruption events. So as the permafrost melts, high pressure reservoirs of free methane gas from any source built up in the last few thousand years will start to erupt, if these three events are the start of a trend.

    If the source of the gas is methane hydrate dissociation, that could be more serious, I think that makes sense. 

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40. KR at 00:48 AM on 21 August, 2014

    Leland Palmer - What I believe scaddenp is saying is that thermogenic methane isn't a factor in climate change, because those sources are not changing, and are really quite unaffected by surface temperatures. Deep thermogenic methane isn't going to bubble out through the permafrost or anything else without unrelated fracture paths going much much deeper. 

    I understand your concern on the impact of methane emissions - but at this point I believe it has been made sufficiently clear that while permafrost melt/decay and methane release will have an impact on total forcing and (after the ~7 year decay time for methane) CO2 levels, it's not going to be a catastrophic impact simply due to the rate of melt, decay, and methane conversion to CO2. The numbers are central to this understanding, and I have to say I consider Archers calculations far more reasonable than yours. 

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41. Leland Palmer at 01:05 AM on 21 August, 2014

    michael sweet-

    Yes, the information is very preliminary, and they seem to be making the wrong measurements, or making the right measurements in the wrong way. 

    If there is a bouyant plume, what matters to the long term release calculation is the methane concentration at the top center of the crater, I think. 

    The best way to do such a calculation would be a fluid dynamics calculation, of course, or computer modeling. 

    I still think it's possible that these craters could be a signifcant long term source of methane, and that the chronic releases might end up being more significant than the initial eruption event- even much more significant, by a large factor. 

    The significance of the "Door to Hell" image is that it makes the methane entering that crater visible. The methane entering that crater, looking  at it visually, could be on the order of ten to 100 cubic meters per second. Turkmenistan, according to Wikipedia, wants to increase its exports to 75 million cubic meters of gas per year, so like Yamal, the ultimate reservoir of gas available is very large.

    It might be possible to get some idea of the chronic emissions by looking at natural gas wells in the area, and seeing what their output is in tons per day. 

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42. Leland Palmer at 06:10 AM on 21 August, 2014

    Hi KR-

    "What I believe scaddenp is saying is that thermogenic methane isn't a factor in climate change, because those sources are not changing, and are really quite unaffected by surface temperatures."

    The sources aren't changing, much, but the permafrost cap is. That is the concern, I think, that high pressure gas that has accumulated over thousands of years could erupt through a weakened permafrost cap. I think that was also Shakova's concern about the East Siberian Arctic Shelf- that the relict undersea permafrost could be weakened, and release reservoirs of high pressure free methane gas.

    It's the accumulate and sudden release possibilities that worry most scientists about methane, in one way or another. Dickens and Hansen, for example, are concerned that the oceanic hydrates, accumulated over millions of years could ultimately be dissociated. 

    If the permafrost weakening process is what is allowing these eruptions, we could see many thousands of them, I think.

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43. scaddenp at 06:57 AM on 21 August, 2014

    Leland, the "door to hell" can maintain production over a long period because it is effectively connected by a "pipe" to a very large high pressure reservoir at depth. Not so with methane hydrates. They are shallow so there is minimal pressure. You may be aware of experiments to mine methane hydrates. If you could get sustained flow rates that easily from melting hydrates, then mining would be easy. 

    While I remain skeptical that frozen tundra is capable of sealing a gas seep, even it were so, we know that the amount of methane going into the atmosphere from such sources has little affect since existing gas seeps contribute little of significance. It is unreasonable to expect there are far more leaky natural gas field under tundra than there are in other parts of the world.

    However "methane hydrate apocolypse" proposes that warming of the arctic will release huge amount of methane over a sufficiently short period of time to significant increase global warming. Critcs such as Archer note that the existance of such large quantities of hydrate remain hypothetical and that being able to melt them fast enough to have significant impact without other externalities is not yet demonstrated. The Yamal craters at this stage dont appear to provide much support to the methane apocalypse given the quantities of methane involved.

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44. KR at 07:15 AM on 21 August, 2014

    Leland Palmer - A relevant paper to this topic is Etiope and Klusman 2002, discussing global CH4 emissions from all sources. These include biogenic and thermogenic methane, and the totals from atmospheric CH4 isotopic ratios indicate that such seeps are a rather small fraction of that emitted from biosphere sources. 

    Reality checking indicates that thermogenic seeps are not major contributors, and that even if there were trapped seeps under permafrost they wouldn't be sufficient to cause a Shakhova type catastrophe - by multiple orders of magnitude. There simply aren't enough seeps globally. 

    Again, I understand your concerns regarding methane emissions - but the numbers show that a methane catastrophe (from either hydrate or seeks) is very unlikely. Your increasingly hypothetical scenarios are just not plausible.

    As Archer has said, our focus should be on our emissions. 

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45. Leland Palmer at 13:01 PM on 21 August, 2014

    "As Archer has said, our focus should be on our emissions."

    No.

    This cold gas eruption release mechanism is a new effect, and we should focus on understanding it. 

    After we understand it, then we can come to some conclusions about how significant it is.

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46. Leland Palmer at 23:39 PM on 21 August, 2014

    scaddenp-

    "Leland, the "door to hell" can maintain production over a long period because it is effectively connected by a "pipe" to a very large high pressure reservoir at depth."

    The initial gas eruption at Yamal might be pretty good evidence that the same is true at Yamal.

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47. KR at 23:45 PM on 21 August, 2014

    Leland Palmer - The Yamal craters are quite interesting, and should certainly be studied. However, concern should be weighted by risk, and by analysis, and reasonable estimations of melt rates, emissions, and methane decay indicate that a Shakhova type methane catastrophe is simply not in the cards. 

    You have posed increasingly implausible scenarios, including permafrost decay and methane percolation rates hugely larger than the physics would indicate, you have conflated thermogenic gases (deep seeps) with biogenic sources (permafrost decay), and from a few crater events have extrapolated ~7 orders of magnitude to a methane catastrophy. You are IMO extending concern far far past what the physics indicate as risks. 

    Given the decay time of methane, I would be far more concerned about subsea hydrates than permafrost decay - and neither is terribly likely if you actually look at the physics and numbers. In the meantime, going overboard with unsupported "we're doomed" scenarios is a distraction from acting where we can, and focusing on controlling our emissions. A focus, I'll point out, that greatly reduces the already low chances of a methane catastrophy by minimizing total climate change. 

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48. scaddenp at 00:34 AM on 22 August, 2014

    If it is connected to deep thermogenic gas, then no problem. No possibility of a methane apocolype from that kind of cause.

    You cant have methane hydrates at depth since only stable in a narrow pressure range. I cant see any plausible mechanism to have long term high rates of methane flow from hydrates.

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49. Leland Palmer at 03:03 AM on 23 August, 2014

    "If it is connected to deep thermogenic gas, then no problem. No possibility of a methane apocolype from that kind of cause."

    I admire your certainty, so soon after the appearance of this new cold eruption phenomenon.  But, you've actually been quite helpful, and have helped advance the "cold eruption as a cause of the circular lake phenomenon associated with Siberian gas fields" hypothesis. 

    I'm afraid, though, I cannot agree with your statement about "no possibility". The permafrost weakening mechanism could likely produce cold eruptions from any high pressure source, and it may be that the thermogenic gas fields have the highest pressure. 

    So, thanks for your help.

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50. scaddenp at 07:16 AM on 23 August, 2014

    You cant have certainty but you can make some ballpark figures. Firstly, there is no trace of a methane catastrophe in previous glaciations when it has been warmer than now. Second, CH4 analysis suggest methane associated with deglaciation is organic, not hydrate or thermogenic. 

    Now, assume that arctic has say twice as much deep leaky gas fields as rest of the world, and using the Etope and Klusman 2002 figures for thermogenic output, and you still cant generate 50GT/y or anything like it. You need 5x as much output from thermogenic to even double atmospheric methane. In short, take a reality check and dont go scaremongering where not needed. Climate activism doesnt need a credubility problem. 

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